textproduct: Quad Cities

KEY MESSAGES

- Heavy rain and thunderstorms are likely for portions of the area this morning and again this evening into the overnight. Localized flash flooding is the primary concern. Rapid rises on small creeks and streams and the flooding of low-lying areas are possible.

- The ongoing Flood Watch has been expanded southward a few counties across east-central Iowa and far northwestern Illinois, and all of it extended through Sunday morning. Rainfall totals of 1-3 inches are still likely (60-80%) in these areas with the potential for localized areas/swaths of 3+ inches.

- The Marginal Risk for isolated severe storms has been removed for much of the area except far southeast Iowa and northeast Missouri.

SHORT TERM /THROUGH TONIGHT/

Issued at 305 AM CDT Sat Sep 19 2026

Looking at the latest water vapor and upper analysis, notice a short wave trof acrs western into central IA, and another one lurking further upstream acrs north central NM. Messy sfc wave with multiple trofs and boundaries pushing east acrs the MO RVR Valley ATTM, and as the feature ridge-rides east-northeast acrs IA today it will try to pull up a warm front through the local CWA at the day progresses, how far north it gets is still a question...I-80 may be it by late afternoon. This will make high temps today a challenge with areas north of the front in clouds and held in the 70s, while areas in the south may get into the low to mid 80s with cloud breaks. Very unseasonable airmass already in place with high sfc DPTs and 2+ inch PWATs(3-4 sigma) in convergent flow currently along and north of the CWA. The ongoing showers and storms ahead of the nearby wave will continue to either seep down from the north or move in from the west with bouts of heavy rain mainly along and north of the Hwy 30 corridor through mid morning. Then maybe a bit of a precip lull during the late morning and early afternoon, but with boundaries and sfc waves on the move acrs the area there will probably be isolated to sctrd precip perculating all day.

Agree with SPC pulling most of the Marginal Risk out of the local area for day 1, although an isolated severe precip loaded downburst or gravity wave enhanced downward wind thrust is still possible today and tonight. Heavy rain and localized flooding remain the primary concern. The advertised 1-3 with localized 4+ inch rainfall amounts by Sunday morning still look on target where repeated showers/storms occur with this kind of PWAT feed.

Tonight...the above mentioned NM wave or some vort max/MCV will look to roll up out of the southwestern plains and ridge-ride it's way acrs IA and northern MO through Sunday morning. Pre-system southwesterly 25+ KT LLJ will again feed and converge high THTA-E air up acrs the region fueling more west-to-east oriented convective bands. LLVL boundaries aligned the same way will be the focus, and it's tough to say exactly where they will lay out but the latest CAM type ensembles suggest maybe along the I-80 corridor. Heavy rain and flash flooding will continue to be a concern along any storm training axis and with some uncertainty on placement and all these convective rounds adding up, have gone ahead and both extended the ongoing flood watch through 12z Sunday, as well as added some more counties to the south of the original headline to include the Cedar Rapids and Quad Cities metro areas for urban flooding potential. The next shift during the day will have to assess the need to expand further west and south depending on focal boundary placement and trends. Some transient fog may occur in precip lull windows this morning and then again late tonight. Low temps an after-thought but most of the area to get down in the 60s.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 305 AM CDT Sat Sep 19 2026

Sunday...A cooler cloudy and post-frontal day with ongoing lift up and over the LLVL baroclinicity which should be settling off to the south of the DVN CWA. Increasing north to northeasterly boundary layer(BL) winds with some spotty rain will make for not a very nice day with a lot of the area held down in the 60s to low 70s. With the upper wave still moving acrs the area, suppose some isolated thunderstorms possible as well as nuisance funnels.

Monday through Friday...Quick look at the longer range suggests that the large upper low/wave currently centered over southern ID will roll eastward acrs the northern plains and toward the upper MS RVR Valley through Tuesday. This may keep cloudy, cooler weather going acrs the area as well as sctrd showers for the early next week period. As this upper wave fills and pulls off to the east, there may be a mid week precip lull until medium range ensemble indicated next passing trof brings the next precip chances by Thu night or next Friday. Cooler temp regime still looks to last much of the week.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 559 AM CDT Sat Sep 19 2026

Rounds of showers and storms are expected throughout the period. BRL may be predominantly VFR with transient bouts of MVFR/IFR in showers/storms at times. Elsewhere, predominantly MVFR to IFR conditions are expected in lower clouds and periodic showers and storms. Timing of the precipitation remains the greatest challenge. Winds will also be challenging. Initially with the passage of an outflow enhanced boundary they will start out from the NE to E around 10 kt with higher gusts. Then, a low pressure system ripples in from the west during the afternoon causing this boundary to return north winds will increase from a southerly direction. Winds then go variable by evening with the wave passing through. There may also be some transient bouts of MVFR/IFR fog mixed in tonight with any precip lull in the weaker wind regime. Late in the TAF winds may increase from the NW to N at CID and DBQ.

HYDROLOGY

Issued at 1040 AM CDT Sat Sep 19 2026

This mornings MCS brought widespread moderate to heavy rain to portions of the area mainly along and north of the Interstate 80 corridor counties. Rainfall amounts in this area were 2 to 4 inches with the heaviest rains falling along and east of of a Manchester to Maquoketa line. This has caused many area creeks to rise this morning and additional rainfall today and tonight increases the threat for flash flooding to occur especially in areas that saw the heaviest rainfall the last 3 days. A Flood Watch for flash flooding potential remains in effect for portions of eastern Iowa and northwest Illinois until 7 AM Sunday.

Widespread heavy rains are leading to rises on area rivers. The heaviest rains the last 3 days have fallen in the Maquoketa, Wapsipinicon, Rock, Pecatonica, English and Cedar River basins. This is leading to forecast rises above flood stage at many locations over the next several days. River flood watches have been issued at many locations on these rivers. Certainty will increase on potential flooding by tomorrow morning after the next round of storms moves across the area tonight into Sunday morning.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Flood Watch through Sunday morning for IAZ040>042-052>054- 065>068. IL...Flood Watch through Sunday morning for ILZ001-002-007-009-015. MO...None.